| 1. |
- Baldursdottir, S, et al.
(författare)
-
Basic principles of neonatal bubble CPAP: effects on CPAP delivery and imposed work of breathing when altering the original design
- 2020
-
Ingår i: Archives of disease in childhood. Fetal and neonatal edition. - : BMJ. - 1468-2052 .- 1359-2998. ; 105:5, s. 550-554
-
Tidskriftsartikel (refereegranskat)abstract
- The original bubble continuous positive airway pressure (bCPAP) design has wide-bore tubing and a low-resistance interface. This creates a stable airway pressure that is reflected by the submersion depth of the expiratory tubing. Several systems with alterations to the original bCPAP design are now available. Most of these are aimed for use in low-income and middle-income countries and have not been compared with the original design.ObjectiveWe identified three major alterations to the original bCPAP design: (1) resistance of nasal interface, (2) volume of dead space and (3) diameter of expiratory tubing. Our aim was to study the effect of these alterations on CPAP delivery and work of breathing in a mechanical lung model. Dead space should always be avoided and was not further tested.MethodsThe effect of nasal interface resistance and expiratory tubing diameter was evaluated with simulated breathing in a mechanical lung model without interface leakage. The main outcome was delivered CPAP and imposed work of breathing.ResultsHigh-resistance interfaces and narrow expiratory tubing increased the work of breathing. Additionally, narrow expiratory tubing resulted in higher CPAP levels than indicated by the submersion depth.ConclusionOur study shows the significant effect on CPAP delivery and imposed work of breathing when using high-resistance interfaces and narrow expiratory tubing in bCPAP systems. New systems should include low-resistance interfaces and wide-bore tubing and be compared with the original bCPAP. Referring to all systems that bubble as bCPAP is misleading and potentially hazardous.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Donaldsson, S, et al.
(författare)
-
COVID-19: minimising contaminated aerosol spreading during CPAP treatment
- 2020
-
Ingår i: Archives of disease in childhood. Fetal and neonatal edition. - : BMJ. - 1468-2052 .- 1359-2998. ; 105:6, s. F669-F671
-
Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic has raised concern for healthcare workers getting infected via aerosol from non-invasive respiratory support of infants. Attaching filters that remove viral particles in air from the expiratory limb of continuous positive airway pressure (CPAP) devices should theoretically decrease the risk. However, adding filters to the expiratory limb could add to expiratory resistance and thereby increase the imposed work of breathing (WOB).ObjectiveTo evaluate the effects on imposed WOB when attaching filters to the expiratory limb of CPAP devices.MethodsTwo filters were tested on three CPAP systems at two levels of CPAP in a mechanical lung model. Main outcome was imposed WOB.ResultsThere was a minor increase in imposed WOB when attaching the filters. The differences between the two filters were small.ConclusionTo minimise contaminated aerosol generation during CPAP treatment, filters can be attached to expiratory tubing with only a minimal increase in imposed WOB in a non-humidified environment. Care has to be taken to avoid filter obstruction and replace filters as recommended.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Donaldsson, S, et al.
(författare)
-
Transition of Extremely Preterm Infants from Birth to Stable Breathing: A Secondary Analysis of the CORSAD Trial
- 2023
-
Ingår i: Neonatology. - : S. Karger AG. - 1661-7819 .- 1661-7800. ; 120:2, s. 250-256
-
Tidskriftsartikel (refereegranskat)abstract
- <b><i>Objective:</i></b> Exploratory secondary analysis of the CORSAD trial compared a new resuscitation system (rPAP) to the standard T-piece system. This analysis focused on the subgroup of infants who were not intubated in the delivery room. The aim was to compare the use of noninvasive positive pressure ventilation (PPV), oxygen saturation, and Apgar scores for the two resuscitation systems during the 30-min intervention period. <b><i>Methods:</i></b> This is secondary analysis of CORSAD trial using data from the intervention period in the delivery room. Infants in the original randomized system groups were divided into intubated and nonintubated groups. For nonintubated breathing infants, we compared demographics, the use of PPV, Apgar scores, and oxygen saturation at 5 and 10 min after birth. Generalized linear models were applied to calculate the risk difference and odds ratio with 95% CI between the two groups. <b><i>Results:</i></b> Among nonintubated infants, the use of PPV repeatedly (defined as PPV with at least 1 min of spontaneous breathing between PPV cycles) was less frequent in the rPAP group (26.8% vs. 43.3%, %RD −16.5, 95% CI [−31.7 to −1.1], <i>p</i> 0.04). The use of PPV after 5 min of age was also less common in the rPAP group (23.2% vs. 38.8%, %RD −15.6, 95% CI [−30.7 to −0.8], <i>p</i> 0.04). There were no statistically significant differences in Apgar scores or oxygen saturation levels between the groups. <b><i>Conclusion:</i></b> In the CORSAD trial, less PPV was needed to establish stable breathing in extremely preterm infants using the rPAP compared to using the standard T-piece without significant difference in Apgar scores or oxygenation.
|
|
| 10. |
- Drevhammar, T., et al.
(författare)
-
Flows and function of the Infant Flow neonatal continuous positive airway pressure device investigated with computational fluid dynamics
- 2020
-
Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227.
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The first dedicated neonatal continuous positive airway pressure (CPAP) device using variable flow was the Infant Flow. The system was pressure stable with a low resistance to breathing. The aim of this study was to describe the flow and function of the Infant Flow geometry using simulated breathing and computational fluid dynamics. Method: The original Infant Flow geometry was used with simulated term infant breathing at three levels of CPAP. The large eddy simulation methodology was applied in combination with the WALE sub-grid scale model. Results: The simulation fully resolved the flow phenomena in the Infant Flow geometry. The main flow feature during inspiration was support by gas entrainment and mixing. During expiration, the jet deflected towards the outlet with unstable impingement of the jet at the opposing edge. Conclusion: The proposed mechanism has previously been based on theoretical reasoning, and our results present the first detailed description of the Infant Flow. The pressure stability was based on a jet supporting inspiration by gas entrainment and then being deflected during exhalation. This confirmed previously assumed principles of function and flows within the geometry and provided a base for further developments.
|
|
